CRYSTAL POLYMORPHOUS FORM A OF 4- HYDROXI- 2- METHYL- N- (2- PYRIDILE)- 2H- 1, 2- BENZOTHIAZINE- 3- CARBOXAMID- 1, 1- DIOXID AND METHOD FOR ITS PREPARATION

摘要

The crystalline polymorphous form is used in the application of medicine and is characterized by the increased stability and biological activity, reduced toxicity and accelerated anti-inflammatory action. It has the following formula:IMAGEand the following specific absorption bands in the infrared spectrum in cm-1: 3324, 1625, 1300, 835 and 695, as well as specific diffraction peaks at the following diffraction angles θ: 4.33, 5.83, 7.25, 9.00. The method involves dissolving 4-hydroxy-2-methyl-N-(2-piridil)-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide in a polar solvent, followed by acidifying the solution to pH 1, rinsing the released product with water until neutral reaction and thermally treating the same at 80-150 degrees C.